Need help with angular velocity

i have a target angle(in radians) that an arm on a character needs to reach, currently im just setting the cframe with the angle like this:
leftArmJoint.C0 = CFrame.new(leftArmJoint.C0.Position)*CFrame.Angles(0,0,angle)

while this gets the arm to the correct angle i would like it to have a velocity so it doesnt just teleport to the correct spot instantly. any help would be appreciated could give more code if that would be important